.ad-left {
    position: relative;
    z-index: 999;
}

.ad-left span {
    line-height: 29px;
}

.ad-left li {
    list-style: none;
    text-align: center;
    box-sizing: border-box;
    width: 200px;
    height: 29px;
    border: #dfdfdf 1px solid;

}

.ad-left li:hover {
    background-color: white;
}

.ad-left>ul>li>ul {
    display: none;
    position: absolute;
    height: 500px;
    background-color: white;
    left: 200px;
    top: 0px;

}

.ad-left>ul>li>ul>li {
    /* position: relative; */
}

.ad-left>ul>li>ul>li>ul {
    display: none;
    position: absolute;
    left: 200px;
    top: 0px;
    height: 500px;
    width: 753px;
    background-color: white;
}